1. Field of the Invention
This invention relates to an open air or outdoor high voltage circuit breaker. In particular, this invention relates to a circuit breaker having shielding electrodes for minimizing or preventing sparking, spray discharges and/or corona discharges in the area of its voltage-carrying outer parts and its connecting elements.
2. Description of the Prior Art
Open air or outdoor high voltage circuit breakers tend to spark and to form corona discharges in the range of their high voltage-carrying parts when they are operated with high voltages for instance above 345 kV. In order to prevent these effects, it is known, e.g. from U.S. Pat. No. 3,973,078, to arrange a disk-shaped electrode between the insulating support for the interrupting units and the box containing these interrupters and carrying high voltage potential. Instead of such disk-shaped shielding electrodes annular electrodes can also be provided. The disk-shaped shielding electrodes are as a rule designed as castings, while the annular electrodes are formed from metal pipes. Furthermore, rolled or pressed sheet metal parts are also known as shielding electrodes.